Closed system adhesive applicator



N0 5, 1968 A. v. PULLINS 3,408,984

CLOSED SYSTEM ADHESIVE APPLICATOR Filed Oct. 25, 1967 2 Sheets-Sheet l A TTOR NEX Nov. 5, 1968 A. v. PULLINS CLOSED SYSTEM ADHESIVE] APPLICATOR 2 Sheets-Sheet 2 Filed Oct. 25, 1967 u' lll mvENToR,A A 774/0 oa M Pa//m A TTORNEY.

United States Patent O 3,408,984 CLOSED SYSTEM ADHESIVE APPLICATOR Atwood V. Pullins, Shawnee Mission, Kans., assignor to Tension Envelope Corporation, Kansas City, M0., a corporation of Missouri Filed Oct. 25, 1967, Ser. No. 677,908 10 Claims. (Cl. 118-259) ABSTRACT F THE DISCLOSURE A driven adhesive applicator for use on an envelope making machine comprises a hollow roller receiving adhesive axially thereinto through a supporting shaft, the roller having a pattern of closely spaced-apart passageways positioned around the periphery thereof. The passageways are plugged, except for those covered by a porous applicator of a desired shape which is mounted on the roller peripheral surface for rolling contact with correspondingly moving envelope blanks.

This invention relates to envelope making machines and more particularly to an improved adhesive applicator for applying adhesive in desired patterns or shapes to moving envelope blanks without certain disadvantages inherent with conventional open gum box applicators.

Envelope making machines commonly incorporate gum supply rollers rotating in and adjacent open gum boxes for transferring adhesive to continuous applicating rollers and to discontinuous rotating applicators often called pickers which, in turn, apply the adhesive to predetermined places on moving envelope blanks. In fabricating -unusual envelopes it is often advantageous to apply adhesive to the 'blanks in unconventional patterns or shapes. This normally requires the machining of special rotating pickers resulting in considerable expense, set-up time, and lost production.

Further, the adhesive in open gum boxes tends to be adversely affected by being constantly exposed to the atmosphere and a difficult maintenance problem is often presented in keeping the various adhesive transferring and applying parts free of excessive adhesive accumulations.

The principal objects of the present invention are: to provide an adhesive applying system wherein the adhesive is not exposed to the atmosphere except at the applicating surface; to provide such structure wherein the shape or pattern of application can be easily varied with a minimum of effort, time, material and expense; to provide such apparatus wherein the adhesive may be continuously agitated without atmospheric exposure; and to provide such an adhesive applicating system which is easily adapted to existing envelope machines and is reliable in operation.

Other objects and advantages of this invention will 'become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.

FIG. l is a fragmentary cross-sectional side elevation showing an adhesive applying station of an envelope making machine incorporating a hollow adhesive applicator embodying this invention.

FIG. 2 is a fragmentary cross-sectional elevational view transversely of the envelope machine showing the adhesive applying apparatus of FIG. 1 with a schematically illustrated pressure circulating system associated therewith.

FIG. 3 is a fragmentary cross-sectional view taken on the line 3-3, FIG. 2, on an enlarged scale, showing ACC details of the applicator including a hollow, adhesive transporting shaft.

FIG. 4 is a fragmentary view of a modified adhesive applicator embodying this invention and characterized by separated supporting shafts.

FIG. 5 is a fragmentary view showing a further modified form of this invention having twoway circulation associated with one supporting shaft and the use of an uncommonly shaped porous applicator.

Referring to the drawings in more detail:

The reference numeral 1 generally indicates a conventional envelope making machine having a frame 2 forming a path of travel 3 for envelope blanks 4 and a station 5 0n the frame for applying adhesive 6 in a predetermined shape or pattern to the blanks 4. Although the blanks 4 are illustrated in spaced-apart relation in the path 3, it is to be understood that the blanks, at times, may also travel through the machine in overlapping relation during adhesive application.

Adhesive applying structure 7, embodying this invention, is adapted for mounting in the station 5 and comprises a roller 8V having a cylindrical peripheral wall 9 with an external curved surface 10 and spaced-apart end walls 11 and 12 defining an enclosed chamber 13. A hollow shaft 14 extends coaxially through the roller 8 and engages suitable collars 15 secured to the end walls 11 and 12 for axially supporting the roller 8. The collars 15 include suitable shaft seals 16 to prevent liquid leakage at the junction between the walls 11 and 12 and the shaft 14.

Mounting blocks 17 are secured to the frame 2 and support suitable bearings 18 which coaxially receive the shaft 14 on opposite sides of the roller 8 for rotatably mounting the roller 8 with the cylindrical wall surface 10 tangentially adjacent the path of travel 3. Suitable drive means, such as a gear 19, is engaged with the shaft 14 and with the drive linkage (not shown) of the envelope machine for rotating the roller 8 at a speed corresponding to the speed of blank travel.

The shaft 1-4 is tubular along the length thereof forming a passageway which, in the embodiment of FIG. 2, extends transversely coaxially entirely across the chamber 13. spaced-apart openings 20' and 21 provide communication between the interior of the shaft 14 and the chamber 13. A suitable plug 22 is located in the shaft 14 between the openings 20 and 21 to prevent a direct ow shunt through the roller 8. Opposite ends 23 and 24 of the shaft 14, in this example, extend beyond the mounting blocks 17 and are engaged with suitable rotary seal joints 25 and 26 which permit liquid to be introduced into the shaft 14 at one end and withdrawn at the other end while the roller 8 is rotated by driving the shaft 14 through the gear 19 or the like.

The rotary joint 25 connects to an input tube 27 which connects to the output of a suitable adhesive pump 28. The pump 28 is fed liquid adhesive 6 from a suitable storage tank 29. The rotary joint 26 connects to an output tufbe 30 which empties into the tank 29 for recirculation through the system by the pump 28. Adhesive 6 which is introduced at the shaft end 23 travels axially into the roller 8 and is discharged into the chamber .13 through the opening 20. Excess adhesive which collects Within the chamber 13 exits into the shaft 14 from which it travels through the rotary joint 26 and back into tank 29 for recirculation through the system. Thus, continuous agitation keeps adhesive components from settling, an important consideration with some types of adhesive. If desired, an appreciable continuous or pulsating pressure may be maintained within the chamber 13 by suitably controlilng the pump and discharge rate. Centrifugal force may also be utilized in dispensing adhesive as described below.

A plurality of spaced-apart passageways 31 extend through the peripheral wall 9 and provide radial communication between the wall surface 10 and the chamber 13. The passageways 31 are positioned in a close repeating sequence and, in this example, entirely surround the roller 8 and have threaded walls 32 as illustrated in FIG. 3.

A porous or liquid permeable applicator 33, which may be chosen from one of many selected materials including synthetic resin Sponges, sintered metallic compositions and absorbent fibrous materials, has a portion 34 of relatively constant maximum thickness, so as to present a surface 35 which is of greatest radius for contacting the envelope blank 4 as it passes thereunder during operation of the envelope machine. The applicator 33 is removably mounted on the surface 10 in a suitable fashion, in this example, by means of clamps 36 which engage a portion 37 of lesser thickness than the portion 34. The clamps 36 are held in position by means of screws 38 which engage selected threaded passageway walls 32. Some or all of the passageways 31 which are covered by the applicator portion 34 are left open so that the adhesive 6 in the chamber 13 may pass through, under gravity flow, positive pressure and/ or centrifugal force, to wet the inside surface of the applicator for absorption and transport to the applicating surface 35. The remaining passageways 31 are blocked with the screws 38 or suitable threaded plugs 39 which are introduced thereinto.

As best illustrated in FIG. 5, the adhesive applicator may assume various unusual continuous or separated shapes with little difficulty by cutting, sawing, milling or otherwise shaping the applicator. In FIG. the applicator 40 is shown in the shape of a U which, for example, may be used in applying a small pocket patch to the respective envelope blanks.

The applicators may be applied to the rollers in multiples if desired so as to reduce the rotational speed per passing envelope blank. In FIG. 1 the applicators are illustrated two-up on the roller whereby two envelope blanks are engaged for each 'rotation of the roller. For continuous application, as in conventional seal flap gumming, the applicator may cover the entire penpheral surface FIG. 4 illustrates a modification of the mounting shaft in that the shaft is not continuous but, rather, is made up of separate tubular stub shafts 41 and 42 having respective spaced-apart ends terminating within the chamber 43. The adhesive is pumped into the chamber through one end 44 and the adhesive overflow is received into the enclosed end 45 of the other stub shaft for recirculation as described in connection with FIG. 2.

In FIG. 5 a solid stub shaft 46 engages one end wall 47 and has rotating support as its only function. However, an enlarged hollow shaft 48, coaxialwith the shaft 46, provides rotational support as well as enclosing a tube 49 therewithin having an outside diameter substantially smaller than the inside diameter of the shaft 48, forming a passageway 50 therebetween. An input tube 51 directs adhesive through openings 52 in the shaft 48, the openings 52 being srrounded'by a rotating, shaft receiving seal structure 53. The adhesive travels through the passageway 50 and into 'therolle'r chamber 54. The tube 49 forms a radial outlet passageway -55 by which excess adhesive may be returned for recirculation, the tube 49 and shaft 48 being respectively-engaged -with a rotating seal joint 56. The inner end 57 of the tube 49, in the illustrated example, is adjacent the cylindrical wall of the roller at the lowermo'st portion,` thus requiring a relatively low level of adhesive I6 within the roller for recirculation.

In operation, the only adhesive which is exposed to the atmosphere is that actually appearing on the surface of the porous applicators, thus, there is little chance for unwanted buildup of adhesive on various operating parts, even when the envelope machine is stopped for an extended period. With many types of gum, the thin crust which will form on the applicator surface will provide an air barrier to protect the remaining adhesive in the system. To begin operation after an extended shut-down, it is only necessary, in many cases, to wipe the surface of the applicator with a, damp cloth to remove the hardened layer of adhesive. In the use of other adhesives, the hardened layer may be peeled off the applicator surface just prior to use.

A suitable backup roller 58 is preferably used at the point of application in the same manner as conventional applicators, the backup roller 58 cooperating with suitable conventional drive rollers 59 or the like for transporting the envelope blanks 4 along the path of travel 3.

It is to be understood that while certain forms of this invention have been illustrated and described, it is not to be limited thereto except insofar as such limitations are included in the following claims.

What I claim and desire to secure by Letters Patent is:

1. For use on an envelope making machine having means defining a path of travel for envelope blanks and a station for applying adhesive to said blanks in said path, adhesive applying structure comprising:

(a) a roller having a curved peripheral wall with an external surface and spaced-apart end walls forming a chamber,

(b) shaft means engaging said roller for rotation with said peripheral wall surface tangentially adjacent said path,

(c) a plurality of spaced-apart passageways extending through said peripheral wall and providing radial communication between said peripheral wall surface and said chamber,

(d) a liquid permeable adhesive applicator, means removably mounting said applicator on said peripheral wall surface, said applicator covering at least one of said passageways, and

(e) plugs in yremaining passageways, whereby liquid adhesive in said chamber wets said applicator through said peripheral wall for application to said blanks.

2. The adhesive applying structure as set forth in claim 1 wherein:

(a) said curved peripheral wall is cylindrical, and

(b) said passageways are positioned in a close repeating sequence surrounding said roller.

3. The adhesive applying structure as set forth in claim 1 wherein:

(a) said passageways each have a threaded wall, and

(b) said plugs have threads engaging saidV threaded walls.

4. The adhesive applying structure as set Iforth in claim 3 wherein:

(a) said means removably mounting said applicator includes screws threadedly lanchored in selected passageways and forming plugs therein.

5. The adhesive applying structure as set forth in claim 1 wherein:

(a) said shaft means is at least partially tubular and communicates into said chamber for introducing liquid adhesive thereinto.

6. The adhesive applying structure as set forth in claim 1 wherein:

l(a) said applicator has an applicating surface of less than full cylindrical shape for applying adhesive in separated shapes.

7. The adhesive applying structure as set forth in claim` 5 wherein:

(a) said shaft means extends through said roller and has spaced-apart openings within said chamber, and

(b) pump means communicating with said shaft means for circulating adhesive within said chamber.

8. The adhesive applying structure as set forth in claim 1 wherein:

(a) said shaft means comprises a pair of hollow stub shafts each having an end positioned within said chamber, said ends being in spaced-apart relation, and

(b) pump means communicating with said stub shafts for circulating adhesive within said chamber.

9. The adhesive applying structure as set forth in claim 1 wherein:

(a) said shaft means includes a hollow shaft having a tube therewithin of substantially smaller outside diameter than the inside diameter of said shaft,

(b) said shaft and tube each opening within said chamber and (c) pump means communicating with said tube and shaft for circulating adhesive within said chamber.

10. For use on an envelope making machine, an

adhesive applicator including:

(a) a hollow cylindrical roller having adhesive contained therein,

References Cited UNITED STATES PATENTS Hoe 101-367 Strawn 101--119 XR Schwab et al. 118-259 XR Weis 118-212 Heonis 101-119 XR CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner. 

